1. Field of the Invention
This invention relates to clutches and, more particularly, to an electromagnetic clutch having increased torque capability.
2. Description of the Prior Art
Mechanical clutches for selectively coupling torque from a rotating shaft, powered by a motor or other power source, to a rotatable load is well known in the art. An input disc connected to the rotating input shaft is mounted parallel to an output disc connected to the load. When the input and output discs are separated the load is isolated from the power source. When the power is to be transferred from the power source to the load the discs are pressed together by various means. If the load connected to the output disc is too large for the amount of friction between the disc, slippage will occur between the disc and the power will not be transferred to the load. Various methods of pressing the discs together to couple the output to the input include using springs, hydraulics or magnetic flux to force the discs together. Prior art electromagnetic clutches employ an input disc and an output disc and a magnetic structure which forces these discs together when a magnetic flux links portions of the magnetic structure. Such a clutch is limited in the amount of force which pulls the discs together and limited in the amount of torque transferred between the input and output shafts connected to these discs.